Lawn mower with cleaning means

ABSTRACT

A lawn mower having a housing and a rotating blade housed therewithin, the housing being provided with a perforated conduit as a portion of its inner surface. Water under pressure is forced through the conduit and exits through the perforations therein, flushing lawn trimmings from the inner surface of the housing.

United States Patent Haapoja et al. 1 Mar. 14, 1972 [54] LAWN MOWER WITHCLEANING 2,984,061 5/1961 Stabnau ..56/320.l MEANS 2,992,524 7/1961Stabnau ..56/320.l l t R d E H R t 2 M 3,040,990 6/1962 Gotti ..239/273C 1 3,214,893 11/1965 Griffin ..56/320.2 1: rick Shem", 3,490,212 1/1970Hengesbach.... ..56/16.8 Ogllwe, 56358 3,535,862 10/1970 Wittwer..56/l7.5 [22] Filed: Dec. 11, 1970 E R K Primary xaminer-Russe insey[211 App], No.: 97,280 Attorney.]ames R. Haller [52] US. Cl 056/3202,56/l6.8, 239/273 ABSTRACT [51] lnt.Cl. ..A0ld 55/18 A lawn mower havmg ahousmg and a rotatlng blade housed [58] Fleld of z g therewithin, thehousing being provided with a perforated conduit as a portion of itsinner surface. Water under pressure is forced through the conduit andexits through theperfora- [56] References Cited tions therein, flushinglawn trimmings from the inner surface UNITED STATES PATENTS 9f thehousmg- 2,936,563 5/ 1960 Blume ..56/12.1 8 Claims, 5 Drawing Figures 3":TL. Am 34 F 30 f 2 l .t:. '\V"44 1 40" 31 g 1 46 1 1 LAWN MOWER WITHCLEANING MEANS This invention relates to rotary power mowers and moreparticularly relates to the cleaning of lawn trimmings from theundersurface of such mowers.

Rotary lawn mowers, powered by gasoline engines or electric motors, arein common usage and normally include a generally circular housing memberwhich houses a centrally located, rotatable blade. A portion of thesidewall of the housing is conventionally formed into a chute throughwhich lawn trimmings are discharged by the rapid rotation of the blade.

Adherence of lawn trimmings to the undersurface (interior surface) ofthe housing has long been an annoying problem. Adherence of such lawntrimmings is especially noticable when the grass being cut is damp. Upondrying, portions of the lawn trimmings may fall to the floor and litterthe storage area in which the lawn mower is stored. Of greaterimportance, heavy accumulation of the adhered trimmings will reduce theefficiency of the mower unless the trimmings are periodically cleanedfrom the undersurface of the mower housing.

The possibility of accidental restarting of the engine or motor duringmanual cleaning of the undersurface of the mower housing presentspotential dangers for the mechanically unskilled. Moreover, manualcleaning is not always feasible for the rather large mowers oftenutilized by local govemmental bodies to trim grass in parks and alonghighways.

A number of solutions to the problem of removing lawn trimmings from theundersurfaces of lawn mower housings have been proposed which avoidmanual cleaning by employing water under pressure as the cleaningmedium. U.S. Pat. No. 3,040,990 relates to a water-spraying device whichcan be attached to the rearmost wall of a lawn mower housing. The waterwhich is discharged into the housing interior is propelled by therapidly rotating blade onto the accumulated grass clippings which are tobe washed away. U.S. Pat. No. 3,214,893 relates to a device includingseries of nozzles which are disposed within the housing interior andprotrude from the undersurface of the top wall of the housing. The waterwhich issues from the nozzles is sprayed against the undersurface of theaccumulated grass clippings and additionally is propelled against thegrass clippings by the force of the rapidly rotating blade for thepurpose of dislodging and washing the clippings away. Each of theso-described devices relies upon the rotating cutting blade to propelwater against the outer surface of the mat of grass clippings. The grassand other foreign matter (e.g., pieces of wire, etc.) which aredislodged from the housing are thus ordinarily propelled through thedischarge chute at high velocity, presenting another source of danger.Moreover, the nozzles which protrude from the undersurface of the mowerhousing as described in U.S. Pat. No. 3,214,893 may serve asobstructions about which matted grass clippings may accumulate.

It is therefore an object of the invention to provide a cleaning meansfor a rotary lawn mower which does not require rotary movement of themower blade during the cleaning operation.

A second object of the invention is to provide a cleaning means for arotary lawn mower which does not require impingement of water upon theouter surface of matted grass clippings within the mower housing.

Yet a third object of the invention is to provide a method for cleaningthe undersurface of a mower housing with water under pressure while thecutting blade, for safety reasons, is motionless.

Briefly, the present invention relates to a cleaning means for removingadhered lawn trimmings from the inner surface of a rotary lawn mower,and to a method for its use. The cleaning means comprises a conduitwhich is disposed within the housing as at least a portion of the innersurface thereof. The conduit is adapted to carry water under pressure,and includes a plurality of perforations therein. The perforations arepositioned to discharge the water under pressure from the conduit intothe interior of the housing from points along the inner housing surfaceso as to flush the lawn trimmings therefrom.

As such, the water under pressure forces the lawn trimmings away fromthe inner surface of the housing. Thus, although the action of therotary blade may be useful to hasten the cleaning operation, it is notnecessary that the blade rotate during this operation, and for reasonsof safety, the mower can thus be shut off during cleaning.

In the drawings:

FIG. 1 is a bottom view of a rotary mower of the invention;

FIG. 2 is a side view, shown partially in cross section taken acrosslines 2--2 of FIG. 1; and

FIGS. 3 is an enlarged, partial cross-sectional view of the circledportion denoted by A" of FIG. 2.

FIG. 4 is a view similar to FIG. 3 but showing another embodiment of theconduit structure.

FIG. 5 is another view similar to FIGS. 3 and 4 but showing stillanother embodiment of the conduit structure.

Referring now to FIGS. 1 and 2, a rotary lawn mower is shown having ahousing 10 which includes top and side walls denoted by 12 and 14,respectively, which walls are joined at 16. During manufacture, the topand sidewalls may be formed as a continuous casting or stamping, and aremore readily seen in FIGS. 3-5. The inner junction of the top (12) andside (14) walls is denoted as 18 in FIG. 2, and it is within this comeror crevice 18 that large quantities of lawn trimmings accumulate.Disposed within the housing 10 as at least a portion 20 of the innersurface thereof is a conduit 22 having perforations (exemplified as 24and 26) therein. The preferred embodiment, as depicted, employs aconduit extending about the inner periphery of the top wall (i.e., inregistration with at least a portion of the length of the joint betweenthe top and sidewalls). It is contemplated, however, that such conduit22, or a plurality of conduits, may be placed elsewhere in the housing,provided that the conduits at least in part form at least a portion ofthe inner surface of the housing, the reason for which will be morefully explained below. Centrally located within the housing is the powerdriven cutting blade 28 which is driven about its axis 30 in thedirection indicated by the arrow 32 by a power source (not shown) suchas a gasoline engine or electric motor. The housing is provided with achute 34 through which lawn trimmings are discharged during thelawn-mowing operation.

For ease of fabrication, it is desired that the conduit 22 be easilyinstalled in the stamped or otherwise formed mower housing 10. Thus,FIG. 3 represents a preferred embodiment wherein the conduit 22 isformed as a separate part during the manufacturing procedure, and issubsequently connected (e.g., by welding or the like) to the innersurface of the mower housing to itself form a portion of the innersurface. In another embodiment, depicted in FIG. 4, theconduit 22 isformed as an integral part of the mower housing and has an inner surface20' which constitutes a portion of the inner surface of the mowerhousing. This embodiment is contemplated as being especially useful inmowers having molded housings of tough plastic material such aspolycarbonate. Yet a third embodiment is shown in FIG. 5 of the drawingwherein the conduit 22 having an outer surface 20" is formed of atubular material, such as copper. In this embodiment, it is highlydesirably that the tubing conform very closely to the shape of the innersurface of the housing, as shown in FIG. 5, so as to itself becomeessentially a portion of the inner housing surface. It will beappreciated that the conduits pictured in the drawing are ofsubstantially uniform cross section along their lengths, and that theconduits of FIGS. 3 and v5 are adapted to be affixed to the housingafter the housing has been formed. It is contemplated that such conduitsmay be removably affixed to the housing by bolts or the like (not shown)so that the housing may be readily disassembled for repair.

As stated above, it is preferred that the conduit be positioned insubstantial registration with at least a portion of the length of thejoint between the top and sidewalls. It is further desirable that theconduit extend at least partially into the chute 34 (as shown at 36 and38 of FIG. 1) so as to permit the removal of lawn trimmings from theinner surfaces of the chute. A water supply tube 40 is provided toconnect the conduit 22 to a suitable source of water under pressure. Oneend 42 of the water supply tube is connected into the conduit, e.g., bywelding. The other end 44 of the water supply tube extends throughpreferably the top wall 12 of the mower housing and terminates in aconnection 46 which is adapted for coupling to a source of water underpressure, such as a garden hose. The connector may contain a filter (notshown) for removal of foreign matter from the water supply.

The conduit 22 bears a series of perforations (exemplified as 24 and 26)for discharge of the water under pressure which is carried by theconduit. These perforations are positioned so as to discharge the waterunder pressure into the interior of the housing from the points alongthe inner housing surface where the perforations are located. The lawntrimmings which accumulate are thus pushed away from the housing surfaceby the water under pressure which is discharged through the perforationsin the conduit. Accordingly, it will be appreciated that the conduititself must form at least a portion of the inner housing surface so thatthe perforations in the conduit will permit water under pressure to bedirected between the housing inner surface and the matted lawntrimmings. The closely fitted tubular conduit 22" depicted in FIG. isthus considered to be a portion of the inner housing surface, since theperforations therein permit water to be directed between the mattedgrass clippings and the inner housing surface.

Thus, in contrast to the cleaning method wherein jets of water arepropelled against the outer surface of matted lawn trimmings whichadhere to the inner surface of the housing (which process requires thatthe mower be running), the present invention operates by providing waterpressure between the matted lawn trimmings and the inner surface of thehousing, thus avoiding the necessity of running the lawn mower duringthe cleaning operation. It is understood, of course, that the cleaningoperation may be hastened by running the mower during the cleaningoperation. Excellent results have been obtained with mowers of theinvention, however, by safely shutting off the power source (e.g., bydisconnect ing a spark plug wire) prior to cleaning.

To insure uniform cleaning of the inner housing surface, it is desirablethat the water pressure in the conduit remain uniform during thecleaning operation. This is readily accomplished by judicious selectionof the conduit diameter and the diameter and number of the perforationstherein. For rotary lawn mowers of the type ordinarily utilized inhouseholds (e.g., having a total blade length of about inches), aconduit having a cross section equivalent in area to that of onehalfinch inner diameter circular tubing yields satisfactory results whenutilized with perforations approximately one thirty-second of an inch indiameter, as described below with reference to FIG. 5. Larger lawnmowers, of course, may require somewhat larger conduits. The requiredsizes of the conduits and perforations therein, and the number ofperforations, can be estimated mathematically using well-knownfluid-flow principles. The inner housing surface 20, 20' which ispresented by the conduit wall is depicted in FIGS. 3 and 4 as beingsubstantially flat in cross section. Although such configuration isdesired for ease of fabrication, such surface may also be concave, orconvex as shown in FIG. 5.

The perforations preferably are arranged in rows along the length of theconduit and are positioned so as to provide control over the directionof the jets of water discharged therethrough. In the most preferredembodiment, two rows of perforations are employed. Referring to FIG. 3,the conduit 22 is positioned in substantial registration with at least aportion of the length of the joint 16 between the top and sidewalls, theconduit thus presenting a portion 20 of the inner housing surface. Theupper row 50 of perforations is adapted to direct a spray of water underpressure in a direction generally parallel to the inner surface of thetop wall 52, whereas the lower row 54 of perforations is adapted todirect water in a direction substantially parallel to the inner surfaceof the sidewall 56. In this embodiment, the water under pressure whichis discharged through the perforations is able to flush matted lawntrimmings from the inner surface of the mower housing at a distance fromthe perforations themselves. Further, it is contemplated that thethus-described directional aspect of the 5 perforations helps to avoidclogging of the perforations with grass during the grass mowingoperation.

It has further been found that an unusually large number of perforationsper unit area is not required for success of the invention. For example,using the embodiment of FIG. 5 (one thirty-second inch diameterperforations), good results can be achieved if the top and bottom rowsof perforations are separated by about three-eighths inch and theindividual perforations in each row are separated by 1 inch. It ispreferred that the spacing between individual perforations not exceedlfzinches, however.

What we claim is:

1. In a lawn mower having a housing and a rotatable blade housedtherewithin,

cleaning means for removing adhered lawn trimmings from the innersurface of said housing, said cleaning means comprising a conduitdisposed within said housing as at least a portion of the inner surfacethereof, said conduit being adapted to carry water under pressure andhaving a plurality of perforations therein positioned to discharge saidwater under pressure into the interior of said housing along andsubstantially parallel to inner surfaces thereof from points along saidinner surfaces so as to flush said lawn trimmings therefrom.

2. The lawn mower of claim 1 wherein said housing includes joined topand sidewalls and wherein said conduit is positioned as a portion of theinner surface of said housing in registration with at least a portion ofthe length of the joint between the top and sidewalls.

3. The lawn mower of claim 2 wherein said perforations are arranged inrows along the length of said conduit, at least two of said rows ofperforations being adapted respectively to direct water under pressurein directions generally parallel to the inner surfaces of said top andsidewalls.

4. The lawn mower of claim 1 additionally comprising a water supplytube, one end of which is connected to said conduit and the other end ofwhich extends exteriorly of said housing and is adapted for connectionto a source of water under pressure.

5. The lawn mower of claim 1 wherein said housing includes joined topand sidewalls and wherein said conduit comprises a perforated water pipepositioned contiguous to said walls along at least a portion of thejoint therebetween so as to itself form a portion of the inner surfaceof said housing.

6. In a lawn mower having a housing and a rotatable blade housedtherewithin, said housing including joined top and sidewalls,

cleaning means for removing adhered lawn trimmings from the innersurface of said housing comprising a. a conduit disposed about saidhousing in substantial registration with at least a portion of thelength of the joint between said top and sidewalls and as a portion ofthe inner surface of said housing, said conduit being adapted to carrywater under pressure and having a plurality of perforations arrangedalong its length in rows so positioned as to direct said water underpressure from said conduit interiorly of said housing from points alongsaid inner surface thereof, at least two of said rows of conduits beingadapted respectively to direct water under pressure in directiongenerally parallel to the inner surfaces of said top and sidewalls; and

. a water supply tube connected at one end to said conduit, the otherend of said tube extending exteriorly of said housing and terminating ina connection adapted for coupling to a source of water under pressure.

7. The lawn mower of claim 6 wherein said conduit and perforations aremutually sized so as to maintain substantially uniform water pressurethroughout said conduit when water 75 under pressure is directed intosaid water supply tube.

8. The lawn mower of claim 7 wherein said perforations are about onethirty-second of an inch in diameter.

UNITED STATES PATENT OFFICE CERTIFICATE OF (IOREEHQN Patent No. 3 648446 Dated March 14 1972 lnventor(s) Raymond E. Haapoja and PatrickSheffler It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

On the title page, the name of the secondlisted inventor should bePatrick Sheffler Signed and sealed this 5th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents USCOMM-DC 60376-5 59 U.Sv GOVERNMENT PRINTING OFFICE I9690-366-334 FORM PO-105O (10-69)

1. In a lawn mower having a housing and a rotatable blade housedtherewithin, cleaning means for removing adhered lawn trimmings from theinner surface of said housing, said cleaning means comprising a conduitdisposed within said housing as at least a portion of the inner surfacethereof, said conduit being adapted to carry water under pressure andhaving a plurality of perforations therein positioned to discharge saidwater under pressure into the interior of said housing along andsubstantially parallel to inner surfaces thereof from points along saidinner surfaces so as to flush said lawn trimmings therefrom.
 2. The lawnmower of claim 1 wherein said housing includes joined top and sidewallsand wherein said conduit is positioned as a portion of the inner surfaceof said housing in registration with at least a portion of the length ofthe joint between the top and sidewalls.
 3. The lawn mower of claim 2wherein said perforations are arranged in rows along the length of saidconduit, at least two of said rows of perforations being adaptedrespectively to direct water under pressure in directions generallyparallel to the inner surfaces of said top and sidewalls.
 4. The lawnmower of claim 1 additionally comprising a water suPply tube, one end ofwhich is connected to said conduit and the other end of which extendsexteriorly of said housing and is adapted for connection to a source ofwater under pressure.
 5. The lawn mower of claim 1 wherein said housingincludes joined top and sidewalls and wherein said conduit comprises aperforated water pipe positioned contiguous to said walls along at leasta portion of the joint therebetween so as to itself form a portion ofthe inner surface of said housing.
 6. In a lawn mower having a housingand a rotatable blade housed therewithin, said housing including joinedtop and sidewalls, cleaning means for removing adhered lawn trimmingsfrom the inner surface of said housing comprising a. a conduit disposedabout said housing in substantial registration with at least a portionof the length of the joint between said top and sidewalls and as aportion of the inner surface of said housing, said conduit being adaptedto carry water under pressure and having a plurality of perforationsarranged along its length in rows so positioned as to direct said waterunder pressure from said conduit interiorly of said housing from pointsalong said inner surface thereof, at least two of said rows of conduitsbeing adapted respectively to direct water under pressure in directionsgenerally parallel to the inner surfaces of said top and sidewalls; andb. a water supply tube connected at one end to said conduit, the otherend of said tube extending exteriorly of said housing and terminating ina connection adapted for coupling to a source of water under pressure.7. The lawn mower of claim 6 wherein said conduit and perforations aremutually sized so as to maintain substantially uniform water pressurethroughout said conduit when water under pressure is directed into saidwater supply tube.
 8. The lawn mower of claim 7 wherein saidperforations are about one thirty-second of an inch in diameter.